After earning his bachelor’s degree at Greenville College in Illinois and his M.A. at Oberlin College, Alfred Joy taught ten years at the American University of Beirut, where he photographed Halley’s Comet in 1910. He spent several summers and one year at Yerkes Observatory and also studied for short periods at Princeton (under Henry Norris Russell) and several European observatories. When World War I prevented his return to Beirut in 1915 he joined the staff of Mt. Wilson Observatory. He remained active there nearly sixty years, although officially retired after 1948. After early solar work with G.E. Hale’s team, Joy applied Walter S. Adams’s method of spectroscopic parallax to determine the distances of thousands of stars. When he retired nearly half of all published radial velocities of stars had been found at Mt. Wilson, largely through his efforts. He measured radial velocities of Cepheid variable stars and confirmed the distance and direction of the Galactic center and the sun’s rate of revolution about it. He specialized in the spectroscopy of variable stars, and also studied spectra of comets and novae. He invented the classification of T Tauri stars and made extensive studies of them. He edited the popular Leaflets of the Astronomical Society of the Pacific from 1945 to 1968.